Radially collapsible and axially retractable building drum



A Filed Hamil s, 1968 Dec. 15, 1970 J QQ Y 3,547,733

RADIALLY COLLAPSIBLE AND AXIALLY RETRACTABLE BUILDING DRUM 7 Sheets-Sheet l INVENTOR. (/E'AN LEBLO/YQ Dec. 15, 1970 LEBLOND 3,547,733 RADIALLY COLLAPSIBLE AND AXIALLY RETRACTABLE BUILDING DRUM Filed Mamh 5, 1968 7 Sheets-Sheet s INVEN'I'UR, J54 [54000 BY Q Dec. 15, 1970 13,547,733

, RADIALLY CQLLAPSIBLE AND AXIALLY RETRACTABLE BUILDING DRUM f Filed March 5, 1968 J. LEBLOND v 'TSheets-Sheet 4 M. I6 AM/1. 4 m Z a B Dec. 1 9 70 J. LEBLOND RADIALLY COLLAPSIBLE AND AXIALLY RETRACTABLE BUILDING DRUM 7 Sheets-Sheet 5 v Filed March 5, 1968 IN V] i/VTUR. (/1941)! LE6L0/v0 19.70 J. LEBLOND RADIALLY ,COLLAPSIBLJE AND AXIALLY RETRACTABLE BUILDING DRUM 7 7 Sheets-Sheet 6 Filed March 5, 1968 Dec. 15, 1970 LEBLQND 3,547,733

RADIALLY COLLAPSIBLE AND AXIALLY RETRACTABL Filed March 5, 1968 E BUILYIZJING DRUM 7 Sheets Sheet 7 United States Patent 3,547 733 RADIALLY COLLAPSlBLE AND AXIALLY RETRACTABLE BUILDING DRIM Jean Leblond, Compiegne, France, assignor to Uniroyal gnglebert France S.A., Paris, France, a corporation of rance Filed Mar. 5, 1968, Ser. No. 710,530 Claims priority, applitiafionzgrance, Apr. 26, 1967, 4 3

Int. (:1. B5911 17/16 U.S. Cl. 156-415 19 Claims ABSTRACT OF THE DISCLOSURE The foregoing abstract is neither intended to define the invention disclosed in this specification, nor is it intended to be limiting as to the scope of the invention in any way.

This invention relates to a building drum that is useful as a support for any material or product which requires changes to be made in the axial or longitudinal dimension of the drum at certain stages during the fabrication of the product.

In the case, for example, of the building of a radial ply tire, a cylindrical carcass having one or more plies interconnecting spaced bead cores is intially formed, then the bead cores are moved toward one another while the central portion of the carcass is expanded to a predetermined diameter to change the cylindrical carcass to toroidal form, and then one or more circumferential breaker plies, sidewalls and a tread are added to the expanded portion of the carcass. These steps are conventionally performed either in a single stage building operation, employing an inflatable (but deformable) drum capable of having its axial length changed, or in a two-stage building operation in which the cylindrical carcass is initally formed on a first, generally rigid drum and is then transferred to a second, inflatable drum to be expanded into toroidal form.

The drum employed in the conventional single-stage building operation usually comprises movable metallic end plates interconnected by an inflatable, cylindrical rubber diaphragm. Since the rubber diaphragm is deformable, cylindrical carcasses built on such drums tend to lack uniformity of diameter, the diameter varying due to such things as stretching of the rubber diaphragm, changes of the tension in the plies being wound on the drum, initial pressure in the drum, and the like. This results in a high scrappage rate for such carcasses and for tires made therefrom. Some attempts to minimize this disadvantage have been made utilizing circumferentially spaced metallic segments to reinforce the rubber diaphragm, the segments being radially collapsible and axially telescopic with the drum end plates to allow relative movement of the end plates toward one another during inflation of the diaphragm. Insofar as these drums do not provide a rigid, circumferentially continuous supporting surface during forming of the cylindrical carcass, however, the uniformity problem still exists, although to a somewhat lesser degree.

In the two-stage building operation, cylindrical carcasses having the desired uniformity of diameter can be built on the rigid, circumferentially continuous drums employed in the first of the two stages of building. However, in this case such carcasses must be handled and stored between the first and second stages of building and then must be remounted on the second stage building drum. This not only leads to extra expense and effort in such handling and storing, but involves lack of uniformity in mounting the carcasses on the second stage drum. This again leads to a high rate of scrappage.

Accordingly the primary objective of the present invention is to obviate the foregoing disadvantages by providing an improved building drum.

Another objective of this invention is to provide an improved building drum capable of making products having a high degree of uniformity.

A further object of this invention is to provide an improved tire building drum suitable for single-stage tire building operations.

Yet another object of this invention is to provide an improved tire building drum which, in one condition of operation, presents a circumferentially continuous, rigid, cylindrical work surface upon which cylindrical tire carcasses may be built and which, in another condition of operation, allows for collapsing of a central section of the drum and for a relative movement of the end sections of the drum toward one another into telescopic relationship with the collapsed central section. of the drum.

A still further object of this invention is to provide an improved tire building drum as in the preceding paragraph, which drum has yet another condition of operation in which the two end sections thereof collapse radially to facilitate removal of a completed tire carcass from the drum.

Further objects and advantages of the invention will become apparent as the following description proceeds.

Briefly stated, and in accordance with one embodiment of this invention, a building drum is provided, comprising a cylindrical body having a plurality of juxtaposed, coaxial cylindrical sections, including a middle section and two end sections, which sections form a rigid, substantially continuous, cylindrical outer surface, the drum in cluding means within the cylindrical body for radially collapsing said middle section and for moving said end sections relatively toward one another without changing their diameter.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as this invention, it is believed that the invention will be better understood from the following description, taken in connection with the accompanying drawings, in which:

FIGS. la, lb, 10, and 1d are diagrammatic sectional elevational views of a building drum in accordance with this invention, FIG. 1a being a diagrammatic longitudinal sectional elevational view of the drum in its axially and radially extended position, FIG. 1b being an enlarged sectional view taken along either of the lines A--A or B-B of FIG. 1a, and FIGS. 1c and 1d being sectional views enlarged in different amounts, taken along the line.

ZZ of FIG. 1a, the latter view showing the drum in its fully collapsed condition;

FIG. 2 is a detailed longitudinal sectional elevational view of the drum in its initial condition of operation, taken along the line XY of FIG. 1d, which line represents two radial planes of the drums displayed by FIGS. 3a and 3b are detailed transverse sectional elevational views of the drum, with parts omitted for clarity, taken along the lines G-G and H-H, respectively, of FIG. 2;

FIGS. 4a, 4b, and 4c are partially diagrammatic longitudinal sectional elevational views of the drum and its operating mechanism, FIG. 4a showing the drum in its initial condition of operation with the middle section thereof in its radially extended position and with the end sections thereof in their radially and axially extended positions, FIG. 4b showing the drum in its second condition of operation with the middle section thereof in its radially collapsed position and with the end sections thereof in their radially extended but axially retracted positions, and FIG. 40 showing the drum in its third condition of operation with the middle section thereof in its radially collapsed position and with the end sections thereof in their axially retracted and radially collapsed positions; and,

FIG. 5 is a schematic diagram showing one form of an electrical control system that may be used to control the various movements of the middle and end sections of the drum.

Referring to FIGS. 1a and 4a, the building drum of the present invention, in its initial condition of operation, comprises a hollow cylindrical body made of an appropriate material such as a metal. This cylindrical body is divided into a plurality of juxtaposed sections including a middle section I and end sections II and III, the various sections being symmetrical to one another with respect to the median plane ZZ and having at their outer ends shoulders E and Ea.

Referring to FIG. 1b, each of the end sections II and III is comprised of a plurality of small segments 23 and a plurality of large segments 24, which large and small segments alternate circumferentially of the end sections, the arrangement being such in the initial operating condition of the drum that a circumferentially continuous, rigid cylindrical surface is formed on each of the end sections II and III. Referring to FIG. 10, a similar arrangement is employed in the middle section I of the drum. Section I comprises a plurality of large segments 25 and a plurality of small segments 26, which large and small segments alternate circumferentially of the middle section I to form, in the initial condition of operation of the drum, a circumferentially continuous, rigid cylindrical surface. The large segments 24 of the end sections differ in size and shape from the large segments 25 of the middle section. Similarly, the small segments 23 of the end sections differ in size and shape from the small segments 26 of the middle section.

Considering the radial plane X-O in each of FIGS. 1b, 1c, and 1d to be one and the same plane, it may be seen that the large segments 25 of the middle section I are in general longitudinal alignment with the small segments 23 of the end sections II and III. Similarly, the small segments 26 of the middle section I are in general longitudinal alignment with the large segments 24 of the end sections II and III. In each of the sections I through III,

the outer lateral surfaces of the small segments (23, 26) and the inner lateral surfaces of the large segments (24, 25) are complementally formed in such a way that the outer lateral faces of the small segments can slide on the inner lateral faces of the large segments during expansion and contraction of the various sections, as shown more clearly in FIG. 1d. Referring to FIG. 2, the outer longitudinal end surfaces of segments 25 and 26 and the inner longitudinal end surfaces of segments 23 and 24 and 23a and 24a, which longitudinally abut one another, are also complementally formed to slide with respect to one another during portions of the movement of the drum between its first and second conditions of operation.

When the building drum is in the initial condition of operation shown in FIGS. 1a, 2 and 4a, the small segments and large segments of the dilferent drum sections I through III abut each other in such a way as to provide the building drum with a circumferentially and longitudinally continuous cylindrical surface having a predetermined fixed diameter. Similarly, the end shoulders E and Ea also are so formed as to provide annular, continuous surfaces.

Referring to FIG. 2, the various sections I, II, and III of the building drum are supported upon and rotate with a shaft S. The shaft S is provided with sleeves 1 and 2 which are splined to the shaft and are axially movable therealong. The small segments 26 (FIGS. 2 and 3a) of the middle section of the drum are each connected to sleeve 1 by means of three arms or links, comprising the pair of links 11 and the single link 13, and are each connected to sleeve 2 by means of a pair of arms or links 12. Similarly, each of the large segments 25 of the middle section I of the drum is connected to sleeve 1 by means of three arms or links, comprising the pair of links 14 and the single link 16, and each large segment 25 is con nected to sleeve 2 by means of a pair of arms or links 15. Each of the various links 11 through 16 is pivotally connected at one of its ends with its respective segment 25 or 26 and is pivotally connected at the other of its ends with its respective sleeve 1 or 2.

The links 11 through 13 connected to the small segments 26 are longer than the links 14 through 16 connected to the large segments 25. Also, the distance between the points 36 and 37 at which the ends of links 11 and 12 are pivotally connected to the segments 26 is larger than the corresponding distance between the points 38 and 39 at which the ends of the links 14 and 16 are pivotally connected to the segments 25. Similarly, the distance between the points 33 and 34 at which the ends of the links 14 and 16 are connected to the sleeves 1 and 2, respectively, is shorter than the distance between the points 30 and 31 at which the ends of the links 11 and 12 are connected to the sleeves 1 and 2, respectively. As a result of this arrangement, any relative axial movement of the sleeves 1 and 2 to the left and right, respectively, as viewed in FIG. 2, will cause the segments 26 to move radially inwardly at a greater rate of speed and to a greater extent than is the case with segments 25, as will appear in greater detail hereinafter.

Considering now the end sections II and III of the building drum, it will be recalled that these seCtions are symmetrical with respect to the median plane ZZ of the drum. Accordingly, a description of one of these sections will also be applicable to the other. To avoid confusion, the end section II will be described, it being understood that the numerals utilized in describing end section II will also apply to end section III, with the sub script a being used to distinguish parts in section III from those in section II.

Referring to FIGS. 2 and3b, it will be seen that each of the small segments 23 of end section II is supported on a sleeve 3 which surrounds the shaft S, the segments 23 being aligned radially with corresponding housings 3 fixed to the sleeve 3. Each small segment 23 is linked to its corresponding housing 3 by a linkage and guide arrangement by means of which the segment is moved radially relative to the sleeve 3. The linkage and guide arrangement for each small segment 23 is the same and the following description of one such arrangement will sufiice for all.

Small segment 23 is provided with a pair of spaced, inwardly directed slides 28 which are fixed thereto and are slidably movable in corresponding guides e formed in housing 3. The radially outer ends of slides 28 support a shaft or pin 40 therebetween, and the pin 40 in turn supports a pair of arms or links 21, each of which is pivotally connected at one of its ends to the pin 40. The other end of each of links 21 is connected to the outer end of a common arm or link 20 by means of one or the other of a pair of shafts or pins 41. The inner end of link 20 is pivotally connected to the housing 3' by means of a shaft or pin 43. An arm or link 19 interconnects the link 20 with a sleeve 4 which encircles and is slidable on sleeve 3. One end of link 19 is pivotally connected to a shaft or pin 42 carried by link 20 and the other end of link 19 is pivotally connected to a shaft or pin 44 carried by the sleeve 4 (FIG. 2).

In order to axially retract the end section II while the middle section I is collapsing, a plurality of pairs of links 17 is provided. The pairs of links 17 are each connected at one of their ends to the pins 43 carried by the links 20 associated with the small segments 23 of end section II. The other ends of the pairs of links 17 are connected to corresponding shafts or pins 50 (FIG. 3a) carried by the links 15. Similarly, a plurality of pairs of links 17a is provided to axially move the end section III while the middle section I is collapsing. The pairs of links 17a are each connected at one of their ends to pins 43a carried by the links 20a associated with the small segments 23a of end section III. The other ends of the pairs of links 17a are connected to corresponding shafts or pins 50a (FIG. 3a) carried by the links 14.

Referring to FIGS. 2 and 3b, it will be seen that each of the large segments 24 of end section II is also supported on the sleeve 3 surrounding shaft S and that the segments 24 are aligned radially with corresponding housings 3 fixed to sleeve 3, as described in connection with the small segments 23. Similarly, each large segment 24 is linked to its corresponding housing 3" by a linkage and guide arrangement which provides for radial movement of the segment relative to the housing. The linkage and guide arrangement for each large segment 24 is the same and the following description of one such arrangement will suflice for all.

Large segment 24 is provided with a pair of spaced inwardly directed slides 28', each of which is fixed thereto and is slidably movable in a respective guide e formed in housing 3". The radially outer ends of slides 28 support a shaft or pin 45 therebetween, and the pin 45 in turn supports a pair of arms or links 22, each of which is pivotally connected at one of its ends to the pin 45. The other end of each of links 22 is connected to the outer end of a common arm or link 29 by means of one or the other of a pair of shafts or pins 46. The inner end of link 29 is pivotally connected to the housing 3" by means of a shaft or pin 48. An arm or link 19' interconnects the link 29 with the sleeve 4. One end of link 19 is pivotally connected to a shaft or pin 47 carried by link 29 and the other end of link 19 is pivotally connected to a shaft or pin 49 carried by the sleeve 4 (FIG. 2).

It should be noted that the links 22 associated with the large segments 24 are longer than the links 21 associated with the small segments 23, and that the links 29 are shorter than the links 20. As a result of this, any relative axial movement of the sleeves 3 and 4 to the right and left, respectively, as viewed in FIG. 2, will cause the segments 23 to move radially inwardly at a greater rate of speed and to a greater extent than is the case with segments 24.

Cylindrical sleeves and 5a are provided which are fixedly connected to and surround the sleeves 3 and 3a, respectively. In addition, cylindrical sleeves 6 and 6a are provided which are fixedly connected to and abut the sleeves 4 and 4a, respectively. Sleeves 3, 4, 5, and 6 are so constructed and arranged as to form air chambers C and D which are employed in radially extending and retracting segments 23 and 24 of end section II. Sleeves 3a, 4a, 5a, and 6a form air chambers Ca and Da which perform a similar function with respect to segments 23a and 24a of end section III.

In the initial condition of operation of the building drum, in which condition the middle and end sections I through III of the drum form a substantially continuous, rigid cylindrical surface, the building drum is ready for the first phase of building a product. In the present example, it is in condition to receive the various structural elements which go into the fabrication of the basic cylindrical carcass of a radial ply tire. At this time, one or more radial plies are wound about the drum, and then head cores are fastened to the plies at the margins indicated at E and Ba.

The second phase of building a radial ply tire requires the shaping of the basic cylindrical carcass into a toroidal form so as to facilitate the application thereto of breaker and tread elements which will transform it into the final carcass. This shaping is obtained by radially collapsing the middle section I and axially retracting the end sections II and III which support the cylindrical carcass, putting the drum into the second condition of operation shown in FIG. 4b, and by simultaneously inflating the carcass with compressed air to expand its central portion. The axial retraction of the end sections of the drum is obtained by causing the middle section thereof to collapse, concurrently moving the two end sections thereof symmetrically closer to the median plane of the drum.

Inflation of the cylindrical carcass may be accomplished by interconnecting suitable passageways (not shown) in the shaft S with a source of pressurized air (not shown) and by having the passageways terminate at, and discharge air into, the interior of the building drum. Suitable cup-shaped end bells (not shown) should be provided, one in sealing engagement with and surrounding the sleeves 4 and 6 and the other in sealing engagement with and surrounding the sleeves 4a and 6a. The cupshaped end bells are preferably disposed with their concave portions facing the median plane of the drum and are preferably movable toward the median plane so as to abut the bead core portions of the cylindrical carcass. In this manner the annular edges of the cup-shaped end bells can seal against the bead areas of the carcass to prevent escape of the air introduced into the drum, thereby to cause such compressed air to inflate the carcass on the drum during the movement of the end sections 2 and 3 toward each other.

Assuming that the various elements to be applied to the carcass while the drum is in its second condition of operation have been affixed thereto, the inflation pressure is then released, the end bells are moved away from the beads and the end sections II and III are caused to radially collapse to bring the drum to its third condition of operation. This condition of operation of the drum serves to allow removal of the completed carcass. After removal of the carcass from the drum, all of the various movements involved in going from the first to the second and then to the third condition of operation of the drum are repeated in reverse order to return the building drum to its first condition of operation.

The foregoing has been presented as a general description of the operation of the drum as used in connection with the building of a tire carcass. A more detailed description of the operation of the drum in such a building operation follows.

Assuming that a cylindrical carcass having bead cores embedded in its marginal portions has been built upon the building drum and that the drum is in its initial condition of operation, and assuming further that the end bell seals (not shown) have been brought into sealing engagement with the bead area of the carcass and that inflation air is starting to be released inside the drum, the sleeves 1 and 2 are next caused to slide with respect to one another and to shaft S, the sleeve 1 moving to the left as viewed in FIG. 2 and the sleeve 2 moving to the right as viewed in FIG. 2. The movement of sleeve 1 to the left drives the pivots 33 and 35 of respective links 14 and 16 to the left and also drives the pivots 30 and 32 of respective links 11 and 13 to the left, away from the median plane ZZ. Similarly, the movement of sleeve 2 to the right drives the pivot 34 of link 15 and the pivot 31 of link 12 in the direction of movement of the sleeve 2.

As a result of the foregoing movements, the group of small segments 26 of the middle section I begin to move radially inward toward the axis of the drum, in a direction perpendicular to the axis, the segments 26 being maintained parallel to the axis during this movement due to the presence of links 13. At the same time, the aforesaid movements of sleeves 1 and 2 cause the group of large segments 25 of the middle section I to also move radially inward toward the axis of the drum, in a direction perpendicular to the axis of the drum, the segments being maintained parallel to the axis due to the presence of links 16.

As indicated earlier herein, the movements of the seg ments 26 and the segments 25 toward the axis of the drum occur at different speeds and in different amounts, the small segments 26 moving inwardly at a higher rate of speed and further than do the large segments 25 in arriving at the final collapsed position of the segments, as illustrated in FIG. 1a.. The differences in the amount of inward movement and in the speed of inward movement of segments 25 and 26 is in a predetermined amount and stems (1) from the fact that the links 11, 12, and 13 (FIG. 2) of segments 26 are greater in length than the corresponding links 14, 15, and 16 of segments 25, (2) from the fact that the pivots and 31 of links 11 and 12, respectively, are spaced farther apart at the start of movement towards the second condition of operation of the drum than are the pivots 33 and 34 of links 14 and 16, respectively, and (3) from the fact that the pivots 36 and 37 of links 11 and 12, respectively, are spaced farther apart than are the pivots 38 and 39 of links 14 and 16, respectively.

As may be noted in FIG. 1d, segments 25 and 26 of the middle section I collapse radially inwardly to a greater extent that do segments 23 and 24 of the end sections 11 and III. This is provided for in order to prevent binding between the segments of section I and the segments of sections II and III, the various segments being in axial telescopic relationship with one another at certain times during the building of a tire carcass.

The movement of sleeves 1 and 2, which is responsible for the inward or collapsing movement of the mid dle section I of the drum, also initiates movement of the end sections II and III of the drum towards one another. This movement results from the fact that links 17 and 17a connect the end sections II and III to links 15 and 14, respectively. Thus, as the pivots 33 and 34 of respective links 14 and 15 separate, due to the movement of the sleeves 1 and 2, links 17 and 17a approach each other, causing the sleeves 3 and 3a to move axially toward the median plane ZZ, in equal amounts, to new positions that are symmetrical with respect to the median plane. The sleeves 4 and 4a also move toward the median plane ZZ in the same amount as do sleeves 3 and 3a. The reason for this is that, at all times other than when end sections II and III are to be collapsed, the chambers C and Ca are pressurized and chambers D and Da are connected to atmosphere to maintain the relative positions of the sleeves 4 and 4a fixed with respect to the sleeves 3 and 311. Accordingly, the aforementioned movement of sleeves 1 and 2 causes the two end sections II and III of the building drum to symmetrically approach the median plane ZZ, without change in diameter, at the same time that the middle section I is collapsing radially inward and at the same time that inflation air is being released inside the drum to expand the central portion of the cylindrical carcass.

At the end of the stroke of sleeves 1 and 2, the building drum reaches its second condition of operation, as shown diagrammatically in FIG. 4b, in which condition of operation the carcass is fully expanded in the desired amount and is ready to receive breaker and tread elements in accordance with known tire building practices. When these elements have been applied to the carcass, that portion of the carcass construction which is accomplished on the drum is completed and the carcass must then be removed from the drum. This is facilitated by collapsing the end sections II and III of the drum, and such collapsing occurs when the drum is shifted from its second to its third condition of operation.

In order to change the drum from its second condition of operation to its third condition of operation, the compressed air in each of chambers C and Ca is exhausted to atmosphere and chambers D and Da are pressurized. As a result of this, sleeves 4 and 6 at one end of the drum and sleeves 4a and 6a at the other end of the drum move axially away from the median plane ZZ. Considering the left end of the drum, as viewed in FIG. 2, the axial movement of sleeve 4 causes the links 19 and 19 to begin moving. As a result of this, the links 20 and 29 of the end section II pivot about their respective axes 43 and 48 and act as crank arms drawing links 21 and 22, which act as connecting rods, radially inward. This causes the segments 23 and 24 to move radially inward, the slides 28 and 28 and guides e and e serving to insure that such segments move in a radial direction only. Similar actions occur concurrently at the right end of the drum and, thus segments 23a and 2411 move radially inward at the same time as do segments 23 and 24.

It should be noted that the ratio of the length of crank arm link 20 to the length of connecting rod link 21 is greater than the ratio of the length of crank arm link 29 to the length of connecting rod link 22. Accordingly, the amount of radially inward movement of the small segments 23 is greater and occurs at a higher rate of speed than the amount and speed of radially inward movement of the larger segments 24. Similar considerations apply in the case of end segments 23a and 24a. When the building drum reaches its third condition of operation, as shown in FIG. 4c, the carcass may be removed, after which the drum would be returned to its initial condition of operation.

In order to return the building drum to its initial condition of operation, the steps taken earlier to arrive at the second and third conditions of operation are performed in reverse order. Thus, the compressed air in chambers D and Da is exhausted to atmospheric and chambers C and Ca are re-pressurized by the addition of compressed air thereto. This causes the segments 23 and 24 of end section II and the segments 23a and 24a of end section III to move radially outward to the positions they take when the drum is in the second condition of operation. At this point, sleeves 1 and 2 can be moved to the right and left, respectively, so as to move link pivots 33 and 34 toward one another and so as to move link pivots 30 and 31 toward one another. This causes the segments 25 and 26 to start moving radially outward to their radially extended position and causes the end sections II and III to start moving away from the median plane ZZ of the drum. As a result of this, the drum is restored to its initial condition of operation and is ready to be used in the building of another carcass.

It will be apparent to those skilled in the art that the length of the building drum may be easily changed to adapt it to build products of different sizes. For this purpose suitable replacement elements (not shown) for the segments 25 and 26 of the middle section I may be supplied, along with replacements for the links 17 and 17a to compensate for the change in length of the segments 25 and 26.

Referring to FIGS. 4a and 4b, the sleeves 1 and 2 are axially moved as necessary to change the drum from its initial condition of operation to its second condition of operation by means of a reversible electric motor M. The motor M drives a lead screw LS by means of an assembly including a torque limiter La and first and second gear wheels Rd and Rd Lead screw LS is provided at one of its ends with a left-hand screw thread and at the other of its ends with a right-hand screw thread, and threaded followers or nuts E and E are provided to cooperate with respective ones of the two sets of threads on the lead screw. Follower E is rigidly connected to sleeve 2 and follower E is rigidly connected to sleeve 1, the arrangement being such that rotation of the motor M in one direction causes the followers E and E to move in equal amuonts both towards each other and towards a median plane V therebetween, and rotation of the motor M in the opposite direction results in equal amounts of movement of the followers E and E both away from each other and away from the median plane V. Limit switches PC30 and FC31 are positioned at the respective ends of travel of follower E for the purpose of generating signals when the follower has reached such points. When limit switch PO31 actuates, as shown in FIG. 4a, it signifies that the building drum has reached its first condition of operation, whereas when limit switch PC30 actuates, as shown in FIG. 4b, it signifies that the building drum has reached its second condition of operation.

Referring to FIG. 4b, an electrically controlled valve, which is provided with solenoids EV1 and EV2, is employed to control the flow of compressed air from a source HP, to the chambers C, Ca, D, and Da, and to atmosphere. When solenoid EV2 is energized and solenoid EV1 is de-energized, the electrically controlled valve takes the position shown in FIG. 4b, allowing high pressure air to flow from the source HP through the valve from right to left, and into chambers Ca and C of the drum. At the same time, the chambers D and Da are connected to atmosphere by means of the valve. When solenoid EV1 is energized and solenoid EV2 is de-energized, the valve takes the position shown in FIG. 40. In this condition of operation high pressure air is conducted from the source HP, through the valve to the chambers D and Da, while the chambers C and Ca are exhausted to atmosphere. With chambers D and Da pressurized, the sleeves 4 and 4a shift axially away from each other, causing the end sections II and III to collapse radially in the manner described hereinbefore and placing the drum in its third condition of operation. The axial movements of sleeves 4 and 4a are sensed by respective limit switches PC32 and PC32a which de-actuate as the sleeves 4 and 4a begin to separate. Switches PC32 and PC32a re-actuate when the drum is returned to its second condition of operation and remain actuated when the drum is returned to its first condition of operation.

Referring to FIG. 5, there has been illustrated an electrical control system which may be utilized to control the operation of the various components of the building drum. Assuming that a suitable control voltage of, for example, 120 volts AC is brought to the control circuits of FIG. 5 by means of the conductors 50 and 51, the building drum may be caused to shift from its initial condition of operation to its second condition of operation by depressing a first foot switch (not shown) whose contacts PS1 close in line L1 of the FIG. 5 control circuits. The closing of contacts PS1 in line L1 causes control relay AV (line L1) to become energized, closing its normally open contacts AV in line L2 and opening its normally closed contacts AV in line L3. The closing of contacts AV in line L2 provides an alternate source of energization to control relay AV in line L1 so that the foot switch PS1 may be released, opening contacts PS1 in line L1, without causing de-energization of relay AV. The energization of relay AV in line L1 also causes three of its normally open contacts (not shown) in an energization circuit to motor M (FIG. 4a) to close, energizing the motor with, for example, three-phase 440 AC voltage. This causes the motor to drive in a first or forward direction such that the threaded followers E and E (FIG. 4a) begin to approach each other. The initial movement of follower E de-actuates limit switch PC31 and causes contacts FC31 in line L3 (FIG. 5) to close without further effect.

The continued rotation of the motor M in the forward direction eventually causes follower E to actuate limit switch PC30 when the drum reaches its second condition of operation. This causes contacts FC3 in line L1 to open and causes contacts PC30 in line L5 to close. The closing of contacts P030 in line L5 is without further effect. The opening of contacts P030 in line L1 causes relay AV to become de-energized. Accordingly, contacts AV in line L2 open and contacts AV in line L3 close without further effect. Also, the three sets of contacts AV (not shown) in the energization circuit to motor M open, deenergizing the motor with the drum in its second condition of operation.

In order to go from the second to the third condition of operation of the drum, a second foot switch (not shown) is depressed, causing its contacts PS2 in line L5 to close and causing its contacts PS2 in line L6 to open, the latter being without further effect. The closing of contacts PS2 in line L5 causes solenoid EV1 (line L5) to become energized through the normally closed contacts PS3 in line L5 and through the now closed contacts PC30 in line L5. Upon energization of solenoid EV1 (line L5), the valve it controls shifts from the position shown in FIG, 4b to the position shown in FIG. 4c, thereby causing chambers D and Da to become pressurized and exhausting chambers C and Ca to atmosphere. Accordingly, the drum shifts to its third condition of operation at this time, de-actuating limit switches FC32 and PC3211, the contacts of which in line L3 open without further effect. Upon release of the second foot switch, its contacts PS2 in line L5 open, de-energizing solenoid EV1 (line L5) without further effect, and its contacts PS2 in line L6 close without further effect, it being understood that the valve controlled by solenoids EV1 and EV2 thereafter remains in the condition shown in FIG. 4c until solenoid EV2 subsequently becomes energized to shift it back to the position shown in FIG. 4b.

In order to return the drum from its third condition of operation to its second and first conditions of operation, a third foot switch (not shown) is depressed. As a result of this, contacts PS3 in line L4 close without further effect, contacts PS3 in line L5 open without further effect, and contacts PS3 in line L6 close, causing energization of solenoid EV2 in line L6. Upon energization of solenoid EV2, the valve it controls shifts from the position shown in FIG. 40 to the position shown in FIG. 41), thereby causing the chambers D and Da to be exhausted to atmosphere while the chambers C and Ca are pressurized by compressed air. As a result of this, the end sections II and III extend radially outwardly to their full diameter, the limit switches PC32 and FC32a becoming actuated at the end of this movement to signify that the drum has returned to its second condition of operation. Accordingly, contacts PC32 and FC32a in line L3 close at this time and, assuming the third foot switch is still depressed and its contacts PS3 in line L4 are still closed, a circuit is completed which energizes relay AR in line L3.

Upon energization of relay AR (line L3), its contacts AR in line L1 open without further effect and its contacts AR in line L3 close, providing an alternate source of energization to relay AR which bypasses contacts PS3 in line L4. In addition, three sets of normally open contacts (not shown) of relay AR in the energization circuit to motor M (FIG. 40) close at this time to energize motor M with the polarity of its three phase energization voltage reversed from the polarity of the voltage previously supplied through the corresponding contacts of relay AV. Accordingly, motor M starts rotating in its second or reverse direction and the followers E and E begin to move away from each other and from the median plane V. The initial movement of follow-er E away from the median plane V causes the limit switch PC30 to become de-actuated. Accordingly, contacts PCStI in line L1 close without further effect and contacts PC30 in line L5 open without further effect. When the motor M has driven fol lowers E and E to their positions of maximum separation, limit switch PC31 becomes actuated, signifying that the drum has returned to the initial condition of operation shown in FIG. 4a. The actuation of limit switch P031 causes its contacts in line L3 to open, de-energizing relay AR in line L3. Upon de-energization of relay AR, its contacts AR in line L3 open without further effect, its contacts AR in line L1 close without further effect, and its contacts AR (not shown) in the energizing the motor its contacts AR (not shown) in the energization circuit 11 to motor M (FIG. 4a) open, de-energizing the motor with the drum in its initial condition of operation, ready to be recycled.

It Will be apparent to those skilled in the art that the building drum described herein is not only useful for building tires but that it may be used whenever it is desired to have a radially collapsible and axially retractable, rigid, substantially continuous cylindrical support for the treatment or shaping of flexible and/ or deformable materials. Moreover, it will be further understood by those skilled in the art that while particular embodiments of this invention have been shown and/or described, various changes and modifications may be made without departing from this invention in its broader aspects.

For example, it is not intended that the invention be limited to the use of segments which alternate in size circumferentially of the drum. The segments of the middle section of the drum may all be of the same size, with alternate segments being movable inwardly at a different time and in a different amount than the remaining segments, to achieve collapsing of the middle section. Alternatively, the segments may alternate in size and the alternate segments may still be moved inwardly at different times and in different amounts than the remaining segments. Similarly, the segments of the middle section, whether all of the same size or of alternating or other variation in size, can be moved inwardly at the same time, with the segments all being concurrently rotated about their respective central longitudinal axes, to achieve a collapsing of the middle section of the drum in the manner of the closing of the iris of a camera.

Accordingly, it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of this invention.

Having thus described the invention, what I claim as new and desire to protect by Letters Patent of the United States is:

1. A radially collapsible and axially retractable building drum, comprising a plurlity of juxtaposed, coaxial cylindrical sections, including two end sections and a radially collapsible middle section, which sections, with said middle section in its expanded condition, together define a rigid, cylindrical outer surface; means for radially collapsing said middle section without radially collapsing said end sections; and means for axially moving said uncollapsed end sections relatively toward one another into telescoped relationship with said collapsed middle section.

2. A building drum as claimed in claim 1, said means for axially moving said end sections being constructed and arranged to axially move said end sections while said means for collapsing said middle section is collapsing said middle section.

3. A building drum as claimed in claim 1, said end sections being radially collapsible; and means connected to but operable independently of said end section moving means for radially collapsing said end sections about said collapsed middle section.

4. A radially collapsible and axially retractable building drum, comprising a plurality of juxtaposed, coaxial cylindrical sections, including two end sections and a radially collapsible middle section, which sections, with said middle section in its expanded condition, together define a rigid, cylindrical outer surface, said middle section being defined by a plurality of circumferentially arranged arcuate segments; means for moving said segments inwardly of said outer surface to collapse said middle section without inwardly collapsing said end sections, said moving means moving said segments in such a manner that adjacent circumferential portions of said segments overlap one another when said middle section is in its collapsed condition; and means for retracting said uncollapsed end sctions axially into telescoped relationship with said collapsed middle section.

5. A building drum as claimed in claim 4, said retract- 12' ing means being constructed and arranged to retract said end sections concurrently with the movement inwardly of said segments.

6. A building drum as claimed in claim 4, wherein each of said end sections is defined by a plurality of circumferentially arranged arcuate segments; and further including means interconnected with said retracting means and said segments of said end sections for moving said segments of said end sections inwardly of said sections to a collapsed position surrounding said collapsed middle section, said last named means moving said segments of said end sections in such a manner that adjacent circumferential portions of said segments overlap one another when said segments are in their collapsed position.

7. A radially collapsible and axially retractable building drum, comprising a plurality of juxtaposed, coaxial cylindrical sections, including two end sections and a radially collapsible middle section, which sections, with said middle section in its expanded condition, together define a rigid, cylindrical outer surface, said middle section being defined by a plurality of arcuate segments arranged in a circumferential sequence; means for moving alternate ones of said segments radially inward in a first predetermined amount without radially collapsing said end sections, means for moving the remaining ones of said segments radially inward in a second predetermined amount without radially collapsing said end sections, said second predetermined amount being different than said first predetermined amount, whereby upon inward movement or" all said segments said middle section is collapsed radially while said end sections remain uncollapsed; and means for retracting said uncollapsed end sections axially into telescoped relationship with said collapsed middle section.

8. A building drum as claimed in claim 7, said means for moving alternate ones of said segments radially inward being constructed and arranged to move said alternate ones of said segments inward concurrently with and at a greater speed than said means for moving the remaining ones of said segments moves said remaining segments inward, and said retracting means being constructed and arranged to retract said end sections concurrently with the radially inward movement of said segments.

9. A building drum as claimed in claim 7, wherein each of said end sections is defined by a plurality of circumferentially arranged arcuate segments; and further including means interconnected with said retracting means and said segments of said end sections for moving said said segments of said end sections radially inward to a collapsed position surrounding said collapsed middle sectlon, said last named means moving alternate ones of said segments of said end sections radially inward to a greater extent than it moves the remaining ones of said segments of said end sections. 10. A radially collapsible and axially retractable buildmg drum, comprising a plurality of juxtaposed, coaxial cylindrical sections, including two end sections and a radially collapsible middle section, which sections, with said middle section in its expanded condition, together define a rigid, substantially continuous, cylindrical outer surface, said middle section being defined by a plurality of small arcuate segments and a plurality of large arcuate segments arranged in an alternating circumferential sequence; means for moving said small and large segments radially inward in respective different amounts without radially collapsing said end sections, whereby upon inward movement of said small and large segments said middle section is collapsed radially while said end sections remain uncollapsed; and means for retracting said uncollapsed end sections axially into telescoped relationship with said collapsed middle section.

11. A building drum as claimed in claim 10, said means for moving said small and large segments moving said small segments radially inward concurrently with and at a greater speed than said large segments, and said retracting means being constructed and arranged to retract said end sections concurrently with the radially inward movement of said large and small segemnts of said middle section.

12. A building drum as claimed in claim 10, wherein each of said end sections is defined by a plurality of small arcuate segments and a plurality of large arcuate seg ments arranged in an alternating circumferential se quence; and further including means interconnected with said retracting means and said small and large segments of said end sections for moving said segments of said end sections radially inward to a collapsed position surrounding said collapsed middle section, said last named means moving said small segments of said end sections radially inward to a greater extent than it moves said large segments of said end sections.

13. A radially collapsible and axially retractable building drum comprising a plurality of juxtaposed, coaxial cylindrical sections, including two end sections and a radially collapsible middle section, which sections, with said middle section in its expanded condition, together define a rigid, substantially continuous, cylindrical outer surface, said middle section being defined by a plurality of small arcuate segments and a plurality of large arcuate segments arranged in an alternating circumferential sequence; means connected to said small segments and to said large segments for simultaneously moving said small segments radially inward in a first predetermined amount and said large segments radially inward in a second predetermined amount without radially collapsing said end sections, whereby upon inward movement of said small and large segments said middle section is collapsed radially while said end sections remain uncollapsed; and means for retracting said uncollapsed end sections axially into telescoped relationship with said collapsed middle section.

14. A building drum as claimed in claim 13, said second predetermined amount being less than said first predetermined amount, said segment moving means moving said small segments radially inward at a greater speed than it so moves said large segments, and said retracting tracting means being constructed and arranged to retract said end sections concurrently with the radially inward movement of said small and large segments of said middle section.

15. A building drum as claimed in claim 13, wherein each of said end sections is defined by 'a plurality of small arcuate segments and a plurality of large arcuate segments arranged in an alternating circumferential sequence; and further including means interconnected with said retracting means and said small and large segments of said end sections for moving said small and large segments of said end sections radially inward to a collapsed position surrounding said collapsed middle section, said last named means moving said small segments of said end sections radially inward to a greater extent than it moves said large segments of said end sections.

16. A building apparatus, comprising: a shaft; a first sleeve coaxially carried on said shaft for rotation therewith; a second sleeve coaxially carried on said shaft for rotation therewith; means for axially moving said sleeves relative to one another; a radially collapsible and axially retractable building drum coaxially carried by said shaft, said drum including first and second end sections. and a radially collapsible middle section, which sections, with said middle section in its expanded condition, together define a rigid, substantially continuous, cylindrical outer surface, said middle section being defined by a plurality of small arcuate segments and a plurality of large arcuate segments arranged in an alternating circumferential sequence; a plurality of first links of a first length interconnecting said first and second sleeves with said large segments; a plurality of second links of a second length greater than said first length interconnecting said first and second sleeves with said small segments, the arrangement being such that axial relative movement of said sleeves with respect to one another causes said small segments to move radially inward from the expanded condition of said middle section at a greater speed and to a greater extent than it causes said large segments to move; and first and second means for moving said respective end sections relatively toward one another, without change of diameter, into telescoped relationship with said middle section when the latter is in its collapsed condition.

17. A building apparatus as claimed in claim 16, said sleeve moving means concurrently moving said first and second sleeves in equal amounts in opposite directions, said first and second means for moving said end sections each including a plurality of arms interconnecting their respective end sections with the aforesaid first; links to move said end sections during movement of said first second sleeves.

18. A building apparatus as claimed in claim 17, wherein each of said end sections is defined by a plurality of small arcuate segments and a plurality of large arcuate segments arranged in an alternating circumferential sequence; and further including means adjacent each of said end sections and interconnected with a respective one of said end section moving means and the small and large segments of a respective one of said end sections for moving said small and large segments of said respective end section radially inward to a collapsed position surrounding said middle section when the latter is in its radially collapsed condition.

19. A radially collapsible and axially retractable building drum, comprising a plurality of juxtaposed, coaxial cylindrical sections, including two end sections and a radially collapsible middle section, which sections, with said middle section in its expanded condition, together define a rigid, continuous, cylindrical outer surface; means for radially collapsing said middle section; and means for moving said end sections relatively toward one another into telescoped relationship with said middle section when the latter is in its collapsed condition, said means for moving said end sections comprising links connecting said end sections to said middle section, said links operating concurrently with said means for collapsing said middle section.

References Cited UNITED STATES PATENTS 2,004,797 6/1935 Pfeifier l56-415 2,339,543 l/1944 Bishop 1564l5 3,405,023 10/1968 Eckenwiler et al. 156-4l5 BENJAMIN A. BORCHELT, Primary Examiner STEPHEN C. BENTLEY, Assistant Examiner US. Cl. X.R. 15 6420 mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. $547,733 Dated December 15, 1970 Inventor I) JEAN L BL ND It in certified that error appears in the above-identified patent and the: said Letters Patent are hereby corructcd u ahmm below:

Column 1 line 26, delete the semi-colon Colu: 1 4, lines 27 and 28, after "first" and before "second", inse: --and--.

Signed and sealed this 26th day of September 1972 (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

